Mudanças hidroclimáticas e no padrão de oxigenação de água de fundo ao longo do limite Triássico-Jurássico na seção Levanto-Maino, Peru: possíveis gatilhos vulcânicos

Abstract

The evolution of the Earth is marked by different periods of mass extinction, the main five being called the Big Five. Often these extinctions are associated with Large Igneous provinces (LIPs). The Triassic-Jurassic transition (Triassic-Jurassic boundary - TJB) presents one of these extinctions, whose characteristics are typical of hyperthermal events. This extinction was associated with the Central Atlantic magmatic province (CAMP) IPL whose consequences include anoxia, climate change and biocalcification crises. Understanding these issues are crucial factors, as we are currently experiencing a new and possible mass extinction where man is the main agent of climate change. Understanding the behavior of past ecosystems and their recovery time will help us understand and predict future impacts of anthropogenic activities. The vast concentration of research in the European and North American basins allows a better understanding of this transition in those localities, and records outside these are still scarce. Here we bring a multiproxy approach that correlates climatic changes, oxygenation conditions and possible distal records of CAMP volcanism in the End Triassic Extinction (ETE) event and in the TJB. Weather and climate records indicate a change in hydroclimatic conditions that start with the negative carbon isotope excursion (CIE) preceding the TJB. Bottom waters remained oxic to disoxic during the TJB, as evidenced by the redox proxies, contrasting with patterns described in shallow marine sessions. Elevated concentrations of Hg and Hg/TOC occurred during the negative CIE, which suggests the recording of CAMP Volcanic activity for the Levanto-Maino session in Peru. Overall, our study highlights the importance of the Levanto-Maino section for understanding the deep marine environmental conditions associated with the ETE and TJB.